EP3860798A1 - Système d'usinage au laser - Google Patents

Système d'usinage au laser

Info

Publication number
EP3860798A1
EP3860798A1 EP19778451.5A EP19778451A EP3860798A1 EP 3860798 A1 EP3860798 A1 EP 3860798A1 EP 19778451 A EP19778451 A EP 19778451A EP 3860798 A1 EP3860798 A1 EP 3860798A1
Authority
EP
European Patent Office
Prior art keywords
mirror
laser
laser beam
homogenization
condenser
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19778451.5A
Other languages
German (de)
English (en)
Inventor
Torsten Leichsenring
Sven Albert
Uwe Wagner
Thomas Schmidt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3D Micromac AG
Original Assignee
3D Micromac AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 3D Micromac AG filed Critical 3D Micromac AG
Publication of EP3860798A1 publication Critical patent/EP3860798A1/fr
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/073—Shaping the laser spot
    • B23K26/0738—Shaping the laser spot into a linear shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/0006—Working by laser beam, e.g. welding, cutting or boring taking account of the properties of the material involved
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B23K26/0643—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising mirrors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B23K26/0648—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising lenses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/0665—Shaping the laser beam, e.g. by masks or multi-focusing by beam condensation on the workpiece, e.g. for focusing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/067—Dividing the beam into multiple beams, e.g. multifocusing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/073—Shaping the laser spot
    • B23K26/0732—Shaping the laser spot into a rectangular shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/352—Working by laser beam, e.g. welding, cutting or boring for surface treatment
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
    • G02B27/0927—Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10—Beam splitting or combining systems
    • G02B27/12—Beam splitting or combining systems operating by refraction only
    • G02B27/123—The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/36—Electric or electronic devices
    • B23K2101/40—Semiconductor devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/36—Electric or electronic devices
    • B23K2101/42—Printed circuits

Definitions

  • the invention relates to a laser processing system for generating a laser beam with a linear beam cross section according to the preamble of claim 1.
  • a workpiece to be processed is arranged in the area of a processing plane and irradiated with the laser beam in such a way that a more or less linear “laser spot” is formed on the surface of the workpiece to be processed.
  • the beam cross section can be characterized by a short beam cross-section axis (hereinafter simply referred to as “short axis” or “short beam axis”) and a perpendicular long beam cross-section axis (hereinafter simply referred to as “long axis” or “long beam axis”).
  • Laser processing systems of this type which can generate a so-called line beam, are used today, among other things, in laser annealing and laser lift-off processes.
  • the width of the beam profile (measured along the short axis) is well below 1 mm, for example in the range of approximately 300 pm, while the length (measured along the long axis) can be up to a few 100 mm, for example in Range of approx. 300 mm.
  • Excimer lasers with wavelengths in the UV range for example at approximately 193 nm, 248 nm or 308 nm, are usually used as laser beam sources.
  • Laser annealing creates a relative movement between the laser beam and the workpiece in the direction perpendicular to the long axis, either by moving the workpiece itself or by moving the laser beam over the surface with the aid of a scanner. A combination of both movements is also possible.
  • This process is used, for example, in the manufacture of flat panel displays.
  • the radiation heats and melts a layer of amorphous silicon and converts it into a polycrystalline Si layer upon re-solidification. This increases the mobility of the charge carriers in the Si layer, which ultimately leads to more efficient and energy-saving displays.
  • Other applications of laser annealing with linear beam profiles are the activation of dopants in a semiconductor layer or the generation of contacts in semiconductor components on SiC wafers (Ohmic Contact Formation, OCF).
  • the boundary layer between the SiC wafer and the metal layer thereon is melted, so that a metal silicide is formed in this area when it cools down.
  • a relative movement is generated between the workpiece and the laser beam.
  • the workpiece to be machined consists of a layer stack that is connected to a growth substrate, for example a GaN layer system on a sapphire substrate. By irradiating the boundary layer between the layer system and the substrate, the layers are detached from the substrate and can then be transferred to another (possibly also coated) substrate.
  • the intensity distribution in the beam cross section in the processing plane should be as uniform or homogeneous as possible. So-called flat-top beam profiles are usually aimed for.
  • a generic laser processing system comprises a laser beam source that generates or emits a raw (not yet prepared) laser beam during operation, as well as downstream devices for beam shaping and homogenization. These devices preferably include a beam expansion system downstream of the laser beam source for receiving the raw laser beam and for generating an expanded laser beam. The beam expansion system is followed by a homogenization system which receives the expanded laser beam and uses it to generate a laser beam with a linear beam cross section in the processing plane that is homogenized with respect to the light intensity distribution.
  • Imaging homogenization systems used here consist of two lens arrays arranged one behind the other and a condenser lens connected downstream.
  • the first lens array divides the incident beam into partial beams
  • the second lens array in combination with the downstream condenser lens, behaves like an arrangement of individual objective lenses that overlays the images of the partial beams in a subsequent superimposition plane (namely the focal plane of the condenser lens).
  • a homogenized flat-top beam profile can be created there.
  • Generic laser processing systems are configured to homogenize the laser beam separately for the long axis and the short axis. This makes it possible to generate different beam dimensions in directions perpendicular to one another.
  • the homogenization system has a first homogenization arrangement for homogenization along the short axis and a second homogenization arrangement for homogenization along the long axis.
  • Each of the homogenization arrangements has optical elements for splitting the laser beam into a plurality of partial beams and a condenser system for superimposing the partial beams in a superimposition plane.
  • the overlay level can be the processing level or an optically conjugate level.
  • DE 10 2007 044 298 B3 describes an arrangement for generating a laser beam with a linear beam cross-section, which has a long and a short beam cross-section axis, in which the laser beam emerging from a laser beam source is homogenized separately with respect to the long axis and the short axis.
  • the invention has for its object to provide a laser processing system of the type described above, which works stably over long periods of time, has a compact structure and offers a high degree of efficiency in utilizing the energy of the laser light source used for the processing.
  • the invention provides a laser processing system with the features of claim 1.
  • Advantageous further developments are specified in the dependent claims. The wording of all claims is incorporated by reference into the content of the description.
  • a laser processing system in which the first homogenization arrangement (for the short axis) has a first condenser system with at least one first mirror and the second homogenization arrangement (for the long axis) has a second condenser system with at least one second mirror.
  • One or more reflective optical components are therefore used in each of the condenser systems.
  • UV radiation can cause degradation of the lens material during operation, for example by producing color centers. This can lead to shorter downtimes.
  • the disadvantages mentioned can be reduced or avoided when using the invention.
  • the service life of the optics can be increased, the optical losses reduced and the number of optical elements required can be limited. Due to the reduced optical losses, a higher energy density can be achieved with the same laser power and the same beam profile on the workpiece. A better efficiency can thus be achieved. Alternatively, a longer beam profile can be generated with the same energy density.
  • a condenser system can be constructed using a combination of one or more lenses and one or more mirrors so that it is a catadioptric optical system.
  • the first condenser system and the second condenser system are each designed as a catoptric optical system, that is to say they are constructed exclusively from mirrors and contain no lenses.
  • the disadvantages associated with lenses can be avoided particularly effectively.
  • the first condenser system and / or the second condenser system preferably has exactly two mirrors.
  • a concave mirror and a convex mirror are combined.
  • a particularly compact construction with little potentially lossy optically functional surfaces (mirror surfaces) can be realized.
  • the optical elements for splitting the laser beam into a plurality of partial beams for each of the axes have a first cylinder lens array and a second cylinder lens array connected downstream, so that the first and the second homogenization arrangement each form a (catadioptric) imaging homogenization system.
  • the optical elements for splitting the laser beam into a plurality of partial beams have only a single cylindrical lens array for each of the axes. which, together with the downstream condenser system, forms a non-imaging homogenization system for the same axis.
  • the aspect ratio is in the range of 100 or more.
  • the aspect ratio can be, for example, in the range from 100 to 1000, possibly also above or below.
  • the first condenser system is designed to generate a (real) intermediate image at a distance from the processing plane and that an (optical) imaging system between the intermediate image and the processing plane for imaging the intermediate image on the processing plane is arranged.
  • This structure takes into account that the condenser systems for the long axis and the short axis can have very different focal lengths, especially when high aspect ratios are aimed for. Using the intermediate illustration for the short axis, these goals can be achieved in a cost-effective manner.
  • the imaging system is designed to image the intermediate image in the first axis without changing the size in the processing plane (1: 1 image in the short axis).
  • the imaging system is designed to image the intermediate image in the first axis without changing the size in the processing plane (1: 1 image in the short axis).
  • enlarging or reducing intermediate images in the short axis are also possible.
  • the long axis is preferably not affected by the imaging system.
  • the imaging system can be constructed using three or more mirrors. According to a further development, however, the imaging system has only two mirrors, namely a first mirror and exactly a second mirror. This results in a simple structure with few components.
  • the first mirror can have a concave mirror surface, the second mirror a convex mirror surface.
  • the imaging system has a symmetrical structure. It can thereby be achieved that typical image errors, which can result when using curved mirrors, such as coma, are compensated for within the imaging system due to the symmetrical structure.
  • the mapping of the intermediate image onto the processing plane can thus be largely free of geometric image errors.
  • a particularly favorable design results if the first mirror has a focal length that corresponds to the distance between the first mirror and the second mirror and twice the focal length of the second mirror, with a distance between the imaging system and the intermediate image being twice the focal length of the first Mirror corresponds.
  • the imaging system is arranged and constructed in such a way that the laser beam is reflected from a first region of the first mirror to the second mirror and from the second mirror to a second region of the first mirror.
  • the first mirror is therefore used twice.
  • the first and the second region can partially overlap one another or be spaced apart from one another without mutual overlap.
  • At least one plane deflection mirror is arranged in the beam path between the laser source and the processing plane, that is to say at least one plane mirror without refractive power.
  • a deflecting mirror is arranged optically between the last optical element with refractive power and the processing plane.
  • the deflecting mirror is thus the last optical element in the beam path that changes the beam path immediately before the processing plane.
  • This deflecting mirror can be fixed, so that there is no mobility except for an adjustment option.
  • this deflecting mirror is movably mounted and can be pivoted in a controlled manner. The deflecting mirror can then be used as a scanner mirror and thus has a double function.
  • a deflecting mirror can also be provided at another position within the beam path.
  • a deflection mirror can be arranged in front of this imaging system.
  • the deflection mirror can in particular be arranged between the intermediate image and the imaging system. This results in greater degrees of freedom for the arrangement and alignment of the imaging system.
  • a preferably interchangeable protective glass can be provided immediately in front of the processing plane, which should let the laser beam pass through as freely as possible and unchanged.
  • the protective glass which can have the shape of a flat plate, can prevent particles or vapors from being deposited on the mirrors during laser processing. Instead, everything ends up on the protective glass, which can be easily replaced if necessary.
  • the generation of a line beam with different dimensions is facilitated by the fact that in the first homogenization arrangement and / or in the second homogenization arrangement, the optical elements for generating the large number of partial beams can be exchanged constructively, wherein they are preferably combined in an assembly which can be exchanged as a whole . This makes it relatively easy to convert to other line dimensions and / or other aspect ratios by exchanging these optical elements.
  • the condenser systems and the imaging system for the short axis do not need to be replaced.
  • the laser processing system is preferably designed in such a way that the line beam or the beam cross section in the processing plane is characterized in that its profile has a flat-top shape with an almost constant energy density over most of the length in both the long axis and the short axis Beam profile and almost vertical drop in energy density in the outer region, wherein preferably a homogeneity deviation along the short axis is 4% or less and / or a homogeneity deviation along the long axis is 1.5% or less. This enables particularly precise machining processes.
  • Fig. 1 shows schematically the structure of a laser processing system and the beam path in a first embodiment
  • Fig. 2 shows a schematic representation of the energy distribution of the raw beam immediately after emerging from the laser beam source
  • FIG. 3 shows a schematic representation of the energy distribution of the laser beam in the processing plane in accordance with a flat-top profile
  • FIG. 10 schematically shows the structure of a laser processing system and the beam path in a second exemplary embodiment.
  • Exemplary embodiments of laser processing systems for generating a laser beam with a linear beam cross section with a short axis (short beam cross-section axis) and a long axis perpendicular thereto (long beam cross-section axis) in a processing plane are described below.
  • Laser processing systems of this type can e.g. used in laser annealing and laser lift-off processes, but also in other applications.
  • the long axis runs parallel to the x-direction
  • the short axis runs parallel to the y-direction
  • the z-axis perpendicular to the processing plane 105 In relation to the system coordinate system KS, the long axis runs parallel to the x-direction, the short axis runs parallel to the y-direction and the z-axis perpendicular to the processing plane 105.
  • the processing plane is the plane in which the beam profile has the desired properties (in particular aspect ratio and Energy distribution).
  • a workpiece to be machined is usually arranged so that
  • FIG. 1 schematically shows the structure of a laser processing system 100 and the beam path that a laser steel LS traverses from the laser beam source 102 to the processing plane 105 in which the surface 112 of a workpiece 110 to be processed is arranged.
  • the laser beam is emitted by the laser beam source 102 as a raw, that is to say not yet processed, laser beam (also referred to as a raw beam) and is then expanded and collimated by a downstream beam expansion system 120 in the form of a telescope.
  • the expanded laser beam is then homogenized by an imaging homogenizer and imaged or focused on the workpiece 1 10 in the region of its surface 1 12 by the optical system.
  • the laser beam source 102 is an excimer laser with a wavelength of 308 nm and a pulse energy of approximately 1000 mJ.
  • the emitted laser beam (raw beam) has an approximately rectangular profile with a length in the range of 30-40 mm and a width of 10-15 mm.
  • the wavelength could also be, for example, 248 nm or 193 nm or another UV wavelength.
  • FIG. 2 A schematic representation of the raw jet is shown in FIG. 2.
  • the raw jet has an approximately rectangular profile, a cross section along the short axis having a Gaussian-like energy distribution.
  • the energy distribution along the long axis already shows greater homogeneity.
  • the raw beam is first expanded through the telescope.
  • the beam expansion system 120 or the telescope 120 consists of two plano-convex cylindrical lenses 120-1, 120-2, the distance between which corresponds to the sum of the two focal lengths (Kepler telescope).
  • the cylindrical lenses are oriented in such a way that the laser beam is widened along the long axis (parallel to the x direction), while no widening occurs perpendicularly to it along the short beam axis.
  • the expansion takes place in order to illuminate the subsequent homogenizer array well - for good beam homogenization, the laser beam should cover as many of the microlenses of the homogenizer array as possible.
  • the width of the laser beam is increased from approximately 50 mm in front of the first telescope lens 130-1 to approximately 90 mm in the area behind the telescope.
  • the beam expansion system could e.g. also have a Galileo telescope with a plano-convex and a plano-concave side. It can e.g. for reasons of better use of space.
  • the actual beam shaping is carried out by a subsequent homogenization system for receiving the expanded laser beam and for generating a laser beam with a linear beam cross section in the processing plane 105 which is homogenized with respect to the light intensity distribution.
  • the homogenization system comprises one Beam expansion system subsequent arrangement of cylindrical lens arrays and condenser systems, which form a separate imaging homogenizer or a separate homogenization arrangement for each of the axes.
  • the homogenization takes place separately for the two axes (short and long axis) or independently of one another, each with its own arrangement of lens arrays and downstream condenser / focusing optics.
  • the homogenization system has a first homogenization arrangement for homogenization along the short axis and a second homogenization arrangement for homogenization along the long axis or that the homogenization system is configured to separate the laser beam for the long axis and the short axis to homogenize.
  • Homogenization arrangements have optical elements for splitting the laser beam into a plurality of partial beams (generally designated by reference numeral 140x) and
  • Condenser system 150x for superimposing the partial beams in an overlay plane.
  • Condenser system 150x for superimposing the partial beams in an overlay plane.
  • the superimposition takes place in the focal plane of the respective condenser system.
  • This focus plane corresponds to the working plane only for the long axis.
  • the focal plane of the condenser system is followed by an image (using the imaging system 160-1), which maps the focal plane to the processing plane.
  • two cylindrical lens arrays 140-1A, 140-1B are first placed in the beam path, which serve as optical elements 140-1 to split the laser beam into a plurality of partial beams for the short axis.
  • These cylindrical lens arrays can either consist of individually manufactured cylindrical lenses which are then placed next to one another, or can also be made from a single substrate which can be processed, for example, mechanically and / or by an etching process. In this application example, a spherical profile of the cylindrical lenses is used.
  • the cylindrical lenses of these arrays with their cylinder axes are also oriented horizontally, namely so that the longer sides of the individual lenses are parallel to the long side of the beam profile.
  • the largest possible number of cylindrical lenses should be illuminated by the incident laser beam.
  • the width of a single cylindrical lens is approximately 1.3 mm, the beam size along the short beam axis at this point in the beam path is approximately 24 mm.
  • Both arrays consist of plano-convex cylindrical lenses with a radius of curvature of 240 mm.
  • the cylindrical lens arrays 140-1 A, 140-1 B and an associated reflective first condenser system 150-1 described later produce an intermediate image ZB homogenized along the short axis at a distance of approximately 400 mm after the condenser system 150-1.
  • cylindrical lens arrays 140-1 A, 140-1 B for the short axis there are two cylindrical lens arrays 140-2A and 140-2B in the beam path, which act as optical elements 140-2 for splitting the laser beam into a plurality of partial beams for the serve long axis.
  • These cylindrical lenses are oriented perpendicular to the cylindrical lenses 140-1 A, 140-1 B for the short axis, they have a width of approximately 1.3-1.5 mm.
  • the lenses of the array 140-2B have an aspherical profile with a conical constant in the range -4 to 0. In other variants, spherical profiles are provided.
  • the radii of curvature of the lenses of the first and second cylindrical lens arrays can be, for example, 20 mm and 5 mm, respectively, in order to produce a beam of approximately 300-370 mm in length, or 12 mm and 20 mm, respectively, for a line beam with a length of approximately 70 - 1 10 mm.
  • Other radii of curvature or combinations as well as other line beam lengths are possible.
  • the first cylindrical lens array 140-2A for the long axis is placed immediately after the second cylindrical lens array 140-1 B for the short axis.
  • the cylindrical lens arrays separate the laser beam for each of the axes into a large number of partial beams.
  • the condenser systems that superimpose these partial beams again consist of two cylindrical mirrors, that is, they are catoptric optical systems.
  • the beam profile shows along the The corresponding axis.
  • a flat-top characteristic ie a beam cross-section with an almost constant energy density over most of the beam profile and steep flanks in the outer areas.
  • the partial beams then diverge again at a greater distance from the focal point.
  • 3 shows schematically the intensity distribution in a flat-top profile.
  • a special feature of the exemplary embodiment is that arrangements with curved mirrors are used as the condenser systems instead of using refractive condenser systems made of lenses, as in the prior art.
  • the first homogenization arrangement (for the short axis) has a first condenser system 150-1 with first mirrors 150-1A and 150-1 B and the second homogenization arrangement (for the long axis) has a second condenser system 150-2 with second mirrors 150-2A and 150-2B on.
  • the focal length of the first condenser system 150-1 (ie the condenser optics for the short axis) is approximately 150 mm, while for the second condenser system 150-2 (for the long axis) it is 2430 mm.
  • the associated condenser system consists of two cylindrically curved mirrors, namely a concave mirror and a convex mirror.
  • the directions of curvature of the condenser mirrors for the long axis are oriented perpendicular to the directions of curvature of the condenser mirrors for the short axis.
  • the axis that describes the respective center of curvature of the mirrors is oriented horizontally for the condenser mirrors of the short axis (parallel to the x direction) and perpendicularly for those of the long axis.
  • the condenser optics for the long beam axis that is to say the second condenser system 150-2, consists of the concave mirror 150-2A and the convex mirror 150-2B, which are arranged in the beam path after the cylinder arrays 140x of the optical elements 140-1, 140-2 .
  • the laser beam then strikes the convex mirror 150-1 A and the concave mirror 150-1 B, which together form the condenser optics for the short beam axis or the first condenser system 150-1.
  • the homogeneous regions generated by the two homogenization arrangements arise at clearly different locations in the beam path - the first homogenization arrangement (for the short axis) generates an intermediate image ZB already at a short distance after the second condenser mirror 150-1B , while the homogenization arrangement for the long axis generates the homogeneous area at a significantly greater distance, namely in the working plane 105.
  • the distance between the focal planes of the short and long axes is approximately 1440 mm in the example described.
  • the intermediate image ZB of the short axis is imaged in the machining plane by an imaging system 160-1.
  • the focal length of the long axis condenser optics is chosen so that the sum of the distance between the two main planes of the condenser optics for the two beam axes, the focal length of the condenser optics for the short beam axis and the transmission length of the imaging system 160-1 (sum of object and Range) correspond.
  • the imaging optics or the imaging system 160-1 for the short axis consists of the two mirrors 160-1A and 160-1 B, ie it has exactly two mirrors.
  • the arrangement is such that the laser beam is reflected twice at the first mirror 160-1A.
  • This first mirror is a larger cylindrical concave mirror, which directs the laser beam onto the second, smaller convex mirror 160-1 B, from where the beam is directed up again the first mirror 160-1A is reflected back.
  • different, non-overlapping areas of the concave mirror surface of the first mirror 160-1A are used in the example. Since the laser beam strikes the first mirror 160-1A twice, the mirror arrangement of the imaging system 160-1 can be regarded as the equivalent of a three-lens transmissive lens.
  • the imaging scale of the imaging system 160-1 for the short axis is 1: 1, ie the intermediate image ZB for the short axis is transferred to the workpiece (into the processing plane 105) without a change in size.
  • the beam path for the long axis is not changed by the imaging system 160-1.
  • the focal length of the first mirror 160-1A corresponds to the distance between the two mirrors and twice the focal length of the second mirror 160-1 B.
  • the distance of the objective or the imaging system from the intermediate image ZB corresponds to twice the focal length of the first mirror 160-1A. Due to the symmetrical structure, many image errors, which arise from the first reflection on the first mirror 160-1A, are compensated for by the impingement on the second mirror 160-1 B and the second reflection on the first mirror 160-1A, in particular coma aberrations.
  • the imaging system 160-1 directs the laser beam onto the workpiece via a flat deflecting mirror 170.
  • the beam could also strike the workpiece directly without using a deflecting mirror.
  • the deflecting mirror 17 is fixedly mounted.
  • the deflecting mirror could also be replaced by a movable deflecting mirror which, in conjunction with an (optional, shown) F-Th eta lens, moves the laser beam over the workpiece, for example through the mirror of a galvanometer scanner or a polygon mirror.
  • the beam profile SP1 represents the beam profile behind the telescope, ie after the beam expansion system 120.
  • the expanded beam SP1 is split into parallel lines by the arrays 140-1 A, 140-1 B for the short axis (beam profile SP2), then the lines become by the arrays 140-2A, 140-2B for the long axis perpendicular to it split into rectangular partial beams (beam profile SP3).
  • the partial beams are superimposed over a longer path again by the condenser systems 150-1, 150-2 and the imaging optics 160.
  • Beam profile SP4 is available according to the condenser system 150-2 for the long axis, beam profile SP5 according to the imaging optics 160.
  • the last beam profile SP6 shows a section of the line beam in the processing plane 105 or on the workpiece surface.
  • the deflection mirror 170 can also be arranged in front of the objective 160, that is to say in front of the imaging system 160.
  • the beam deflection allows, for example, a vertical or almost vertical arrangement of the imaging system 160, which can possibly make better use of the available installation space. In this case, the laser beam coming from the objective 160 hits the workpiece directly without further deflection.
  • a second deflection mirror between the objective and the workpiece could also be provided.
  • the workpiece 110 is moved linearly in one plane (x-y plane) obliquely to the plane of the incident beam.
  • the oblique incidence ensures that back reflections from the workpiece surface cannot get into the beam path of the laser processing system.
  • the line beam generated covers the entire width of the workpiece to be machined or the area of the workpiece to be machined, so that the workpiece only has to be moved along an axis.
  • the described line systems for the short and long axes create the desired line beam on the workpiece. In some exemplary embodiments, including the examples shown here, this has a length of 300-370 mm and a width of 330 ⁇ m.
  • the line beam is characterized in that its profile has a flat-top shape in both the long and the short beam axis (almost constant energy density over the majority of the beam profile, almost vertical drop in energy density in the outer regions) a homogeneity deviation of ⁇ 4% along the short axis or even ⁇ 1.5% along the long axis.
  • the beam profile on the workpiece is shown schematically in FIG. 3 (the aspect ratio of the line beam is not to scale in the figure, however).
  • a beam expansion system is provided in each of the exemplary embodiments shown.
  • the aim of the beam expansion is to create a beam that fills the first homogenizer array as much as possible.
  • There should be as many microlenses as possible incident beam "hit" because the homogeneity of the output beam is the better, the more microlenses are covered by the incident beam. Without beam expansion, the homogeneity is usually worse.
  • a homogenizer could also be used without an upstream beam expansion. If the requirements for homogeneity are not too high, a beam expansion upstream of the beam splitting, i.e. a beam expansion system downstream of the laser beam source for receiving the raw laser beam and for generating a widened laser beam, may be dispensed with.
  • Imaging homogenization systems are provided in each of the illustrated exemplary embodiments.
  • An imaging homogenization system or an imaging homogenizer has two lens arrays and a downstream condenser system.
  • the lenses of the second lens array map the corresponding lens apertures of the first lens array; these individual images are then overlaid by the condenser system in its focal plane.
  • a non-imaging homogenizer (or a non-imaging homogenization system) can also be provided in some cases.
  • a non-imaging homogenizer consists of only one lens array and a downstream condenser system.
  • Non-imaging homogenizers are generally particularly well suited for illuminating the largest possible areas, while imaging homogenizers can achieve better homogeneity.
  • the line size can be varied more easily, e.g. by changing the spacing of the lens arrays. This can also be used to compensate for manufacturing tolerances.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Laser Beam Processing (AREA)

Abstract

L'invention concerne un système d'usinage au laser (100) permettant de produire un faisceau laser de section transversale linéaire présentant un petit axe et un grand axe perpendiculaire à celui-ci dans un plan d'usinage (105). Le système comporte une source de faisceau laser (102) servant à produire un faisceau laser brut, un système d'expansion de faisceau (120) placé en aval de la source de faisceau laser et servant à la réception du faisceau laser brut et à la production d'un faisceau laser évasé ainsi qu'un système d'homogénéisation placé en aval du système d'expansion de faisceau et servant à la réception du faisceau laser évasé et à la production d'un faisceau laser homogénéisé par rapport à la répartition d'intensité lumineuse et présentant une section transversale de faisceau linéaire dans le plan d'usinage. Le système d'homogénéisation comprend un premier ensemble d'homogénéisation servant à l'homogénéisation le long du petit axe et un deuxième ensemble d'homogénéisation servant à l'homogénéisation le long du grand axe. Chacun des ensembles d'homogénéisation comprend des éléments optiques (140-1, 140-2) servant à la dispersion du faisceau laser en une pluralité de sous-faisceaux et un système condenseur (150-1, 150-2) servant à superposer les sous-faisceaux dans un plan de superposition. Le premier ensemble d'homogénéisation comprend un premier système condenseur (150-1) doté d'au moins un premier miroir (150-1A, 150-1B) et le deuxième ensemble d'homogénéisation comprend un deuxième système condenseur (150-2) doté d'au moins un deuxième miroir (150-2A, 150-2B).
EP19778451.5A 2018-10-02 2019-09-20 Système d'usinage au laser Pending EP3860798A1 (fr)

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DE102018216940.3A DE102018216940A1 (de) 2018-10-02 2018-10-02 Laserbearbeitungssystem
PCT/EP2019/075349 WO2020069885A1 (fr) 2018-10-02 2019-09-20 Système d'usinage au laser

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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102020116268A1 (de) * 2020-06-19 2021-12-23 Ii-Vi Delaware, Inc. Fasergekoppelter laser mit variablem strahlparameterprodukt
WO2022046575A1 (fr) * 2020-08-22 2022-03-03 Pavilion Integration Corporation Systèmes, dispositifs et procédés de génération de faisceaux laser
TWI762299B (zh) * 2021-05-03 2022-04-21 國立臺灣科技大學 基於軌道角動量之非對稱式雙向無線光通訊系統
DE102021119195A1 (de) 2021-07-23 2023-01-26 Trumpf Laser Gmbh Verfahren und Vorrichtung zur Werkstückbearbeitung mit einem, durch eine Scanneroptik geführten, verbreiterten Laserstrahl

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS636540A (ja) 1986-06-27 1988-01-12 Komatsu Ltd インテグレ−タ
JP2655465B2 (ja) * 1993-01-20 1997-09-17 日本電気株式会社 反射型ホモジナイザーおよび反射型照明光学装置
JP4238390B2 (ja) * 1998-02-27 2009-03-18 株式会社ニコン 照明装置、該照明装置を備えた露光装置および該露光装置を用いて半導体デバイスを製造する方法
US6856630B2 (en) * 2000-02-02 2005-02-15 Semiconductor Energy Laboratory Co., Ltd. Beam homogenizer, laser irradiation apparatus, semiconductor device, and method of fabricating the semiconductor device
TW558861B (en) 2001-06-15 2003-10-21 Semiconductor Energy Lab Laser irradiation stage, laser irradiation optical system, laser irradiation apparatus, laser irradiation method, and method of manufacturing semiconductor device
DE102007044298B3 (de) * 2007-09-17 2009-02-26 Coherent Gmbh Verfahren und Anordnung zum Erzeugen eines Laserstrahls mit einem linienhaften Strahlquerschnitt
DE102009037112B4 (de) 2009-07-31 2012-10-25 Carl Zeiss Laser Optics Gmbh Optisches System zum Erzeugen eines Lichtstrahls zur Behandlung eines Substrats
US8946594B2 (en) 2011-11-04 2015-02-03 Applied Materials, Inc. Optical design for line generation using microlens array
DE102014116957A1 (de) 2014-11-19 2016-05-19 Trumpf Laser- Und Systemtechnik Gmbh Optisches System zur Strahlformung
US10016843B2 (en) * 2015-03-20 2018-07-10 Ultratech, Inc. Systems and methods for reducing pulsed laser beam profile non-uniformities for laser annealing
CN104777719A (zh) 2015-04-14 2015-07-15 中国科学院上海光学精密机械研究所 深紫外光刻机照明系统光瞳面光强分布的控制装置
DE102016006960B4 (de) * 2016-06-08 2019-05-02 Innovavent Gmbh Optisches System zum Beseitigen von Inhomogenitäten in der Intensitätsverteilung von Laserstrahlung, Anlage zur Bearbeitung von Dünnfilmschichten mit einem optischen System und optisches Verfahren
JP6804224B2 (ja) 2016-06-22 2020-12-23 三菱重工業株式会社 レーザ加工装置およびレーザ加工方法
DE102017210241B4 (de) * 2017-06-20 2019-10-17 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Optische Anordnung zur Umformung des Intensitätsprofils eines optischen Strahls
CN107433396B (zh) 2017-07-14 2018-10-09 中国科学院微电子研究所 一种激光加工晶圆的装置及方法
DE102017115964B4 (de) 2017-07-14 2020-04-02 LIMO GmbH Vorrichtung zur Erzeugung einer linienförmigen Intensitätsverteilung einer Laserstrahlung
CN107515471B (zh) 2017-10-13 2024-02-13 中国科学院云南天文台 一种提高激光输出能量分布均匀性的装置及方法

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US20210402515A1 (en) 2021-12-30
KR20210066853A (ko) 2021-06-07
WO2020069885A1 (fr) 2020-04-09
TW202021706A (zh) 2020-06-16
DE102018216940A1 (de) 2020-04-02

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